1. Field of the Invention
The present invention relates to fluid couplings or fittings for connecting bellows-shaped metallic corrugated pipes.
2. Description of the Related Art
In recent years, metallic corrugated pipes have come to be used more and more as replacements for conventional steel pipes used as indoor gas piping in houses and the like, since they are flexible and thus more workable However, since corrugated pipes have a bellows-shaped outline with top and root portions arranged alternately they are less easy to connect to each other or to other pipes than are conventional steel pipes. For this reason, fluid couplings used with corrugated pipes tend to have connecting mechanisms which are complicated and therefore difficult and time-consuming to operate As a result, there is considerable demand for the development of a fluid coupling which will permit corrugated pipes to be more easily connected to each other and to other types of pipe.
Moreover, there is demand for the elimination of the rubber gaskets which are conventionally used to seal most corrugated pipes in order to prevent gas leakage, since in the event of a fire breaking out, the rubber gaskets will most likely be melted by the heat produced, thereby causing gas to leak out and further feed the fire.